After three years of ecological restoration efforts, China has brought back lucid water, green banks, clean beaches, and beautiful bays to Bohai Sea, a semi-enclosed inland sea in the country.
Endowed with unique natural ecology and prominent geographic advantages, the Bohai Sea is of great strategic importance.
However, the sea used to face a grim situation of environmental and ecological protection due to serious land-based pollution.
In 2018, China launched a campaign to improve the water environment of the Bohai Sea region, and the campaign is a complete success.
China implements a four-tier water quality classification system for seawater and a five-tier classification system for surface water, with GradeⅠbeing the best. Data from China’s Ministry of Ecology and Environment (MEE) indicate that the proportion of water of “fairly good quality” (GradeⅠand GradeⅡ) in the Bohai Sea coastal waters had grown to 82.3 percent last year, 9.3 percentage points higher than the target of 73 percent set for the campaign and 15.3 percentage points higher than the figure recorded in 2017.
Besides, all the key targets and tasks of the campaign, including investigation into sewage outfalls into the sea, eliminating poor-quality surface water below Grade V in state-controlled cross sections of rivers flowing into the sea, and ecological remediation and restoration of coastal wetlands and shorelines, have been completed to a high standard.
The three-year battle to improve the water environment of the Bohai Sea region involved unprecedented efforts to coordinate pollution prevention and control for land and sea and has resulted in an unprecedented improvement in the quality of offshore waters, said Zhang Zhifeng, vice director of the Department of Marine Ecology and Environment of the MEE.
As one of China’s seven landmark campaigns for pollution prevention and control and the country’s first battle against marine pollution during its 13th Five-Year Plan period (2016-2020), the campaign launched to improve the water environment of the Bohai Sea region bears great significance and has far-reaching influence, Zhang added.
Over the past three years, the three provinces and one municipality adjacent to the Bohai Sea, namely China’s Liaoning, Hebei, and Shandong provinces and Tianjin municipality, have coordinated land and marine development, solved ecological problems troubling the sea and relevant rivers, and addressed both symptoms and root causes of the problems.
By formulating and implementing targeted measures and plans to improve the water quality of state-controlled rivers that flow into the sea, or rivers that flow into the Bohai Sea with cross sections included in the country’s national surface water quality monitoring system, relevant governments have strengthened comprehensive river basin management of state-controlled rivers and other rivers that flow into the sea.
Tianjin municipality has advanced the comprehensive management of its 12 rivers that flow into the Bohai Sea by making targeted efforts, leveraging engineering methods and carrying out projects according to the respective characteristics of these rivers.
The proportion of water of “fairly good quality” in the Bohai Sea coastal waters in Tianjin had risen from 16.6 percent in 2017 to 70.4 percent in 2020, when the water quality of the state-controlled water sections of all the 49 rivers that flow into the sea was raised to above Grade Ⅴ, according to data from the MEE.
The overhaul of sewage outfalls into the sea is an important move in promoting targeted, science-based, and law-based pollution control for ecological and environmental restoration of the Bohai Sea.
In January 2019, a pilot investigation into sewage outfalls into the sea led by the MEE kicked off in Tangshan city of Hebei province. Three months later, the activity began to be comprehensively carried out in the 13 cities of the Bohai Sea region, involving 3,600 km of shorelines.
Through a three-tier investigation mechanism featuring remote sensing by unmanned aerial vehicles, on-site investigation by personnel, and quality control and verification by experts, the three provinces and Tianjin municipality located near the Bohai Sea comprehensively traced the sources of and investigated into sewage outfalls into the sea, discovering a total of more than 18,000 outfalls of such kind.
The overhaul has gradually taken effect, with the proportion of water of “fairly good quality” in the Bohai Sea coastal waters in Tangshan standing at 100 percent in 2020 and the first half of 2021.
Laizhou, a county-level city of Shandong province located on the shore of Laizhou Bay, one of the three major bays of the Bohai Sea, has effectively reversed the marine environmental pollution of the Laizhou Bay and given it a beautiful new look by improving a marine sanitation mechanism, under which it has designated personnel for cleaning waste on every beach and area of the bay.
In March, May, and August of 2021, the proportion of water of “fairly good quality” in the Laizhou Bay offshore waters reached 71.6 percent, 51.4 percent, and 77.7 percent respectively, 39.6 percentage points, 21.4 percentage points and 11.8 percentage points higher than the average of corresponding figures registered between 2018 and 2020.
The three provinces and Tianjin municipality adjacent to the Bohai Sea have all established regular working mechanism for marine sanitation and made great efforts to enhance infrastructure construction and advance timely removal and regular oversight of marine litter, according to Zhang.
These provinces and the municipality have restored 8,891 hectares of coastal wetlands and 132-km coastline, exceeding the target of 6,900 hectares of coastal wetlands and 70 km of coastline.
In addition, 37.5 percent of the offshore areas of the Bohai Sea have been included in their marine ecological protection red-line zones.